A. Field of the Invention
The present invention relates to a communication system, and is more particularly related to retrieving secure web content using proxy servers.
B. Description of Related Art
The maturity of electronic commerce and acceptance of the Internet as a daily tool by a continually growing user base of millions of users intensifies the need for communication engineers to develop techniques for enhancing network performance. With the advances in processing power of desktop computers, the average user has grown accustomed to sophisticated multimedia applications, which place tremendous strain on network resources (e.g., switch capacity). Also, because the decrease in application response times is a direct result of the increased processor performance, the user has grown less tolerant of network delays, demanding comparable improvements from the network infrastructure. Therefore, network performance enhancing mechanisms are needed to optimize efficiency and reduce user response times. These mechanisms are imperative in systems with relatively high network latency, such as a satellite network.
FIG. 1 is a diagram of a conventional communication system for providing retrieval of web content by a personal computer (PC). PC 101 is loaded with a web browser 103 to access the web pages that are resident on web server 105; collectively the web pages and web server 105 may represent a “web site.” PC 103 may connect to a wide area network (WAN) 107, which is linked to the Internet 109. The above arrangement is typical of a broadband connection. Other connection types include dial-up connections (not shown) to the Internet 109 for access to the Web. The phenomenal growth of the Web is attributable to the ease and standardized manner of “creating” a web page, which can possess textual, audio, and video content.
Web pages are formatted according to the Hypertext Markup Language (HTML) standard which provides for the display of high-quality text (including control over the location, size, color and font for the text), the display of graphics within the page and the “linking” from one page to another, possibly stored on a different web server. Each HTML document, graphic image, video clip or other individual piece of content is identified, that is, addressed, by an Internet address, referred to as a Uniform Resource Locator (URL).
In a typical transaction, the user enters or specifies a URL to the web browser 103, which in turn requests a URL from the web server 105 using the HyperText Transfer Protocol (HTTP). The web server 105 returns an HTML page, which references numerous embedded objects (i.e., web content), to the web browser 103. Upon receiving the HTML page, the web browser 103 processes the page to retrieve each embedded object. The retrieval process requires the establishment of separate communication sessions (e.g., TCP (Transmission Control Protocol) connections) to the web server 105. That is, after an embedded object is received, the TCP connection is torn down and another TCP connection is established for the next object. Given the richness of the content of web pages, it is not uncommon for a web page to possess 30 or more embedded objects. This arrangement disadvantageously consumes network resources, but more significantly, introduces delay to the user.
Delay is further increased if the WAN 107 is a satellite network, as the network latency of the satellite network is typically longer than terrestrial networks. In addition, because HTTP utilizes a separate TCP connection for each transaction, the large number of transactions amplifies the network latency. Further, the manner in which frames are created and images are embedded in HTML requires a separate HTTP transaction for every frame, compounding the delay.
It is often desirable to transmit certain web content between the end-user and the web server in a secure manner. Web-based electronic commerce applications are an example of a class of applications in which sensitive financial information is transmitted over the web. The secure HTTP (HTTPS) protocol is often used to securely transmit such information. An HTTPS session is essentially an HTTP connection established over a Secure Socket Layer (SSL) connection. SSL is a well known protocol for encrypting data sent between clients and servers.
HTTPS connections require additional network overhead to set-up and maintain. Accordingly, in networks in which latency is an issue (e.g., satellite networks), HTTPS connections can even further exacerbate latency.
Based on the foregoing, there is a clear need for improved approaches for retrieval of content within a communication system.